Concentration of oxide copper ores by flotation separation

ABSTRACT

Oxide copper ores in subdivided form may be concentrated in a flotation separation process by slurrying said ores in an aqueous solution of a flotation reagent followed by generating gas bubbles in the slurry to float the oxide copper and recovering the concentrated oxide copper from the surface of the slurry, wherein the floatation reagent is   II. condensation reaction products of A. polybasic amines of the structure H2N(CH2CH2NH)nH, and B. organic halides of the structure R2Y

United States Patent 11 1 [111 3, 34,533

McGuire et al. [4 Sept. 10, 1974 CONCENTRATION OF OXIDE COPPER 1,120,394 12/1961 Germany 209/166 ORES BY FLOTATION SEPARATION [75] Inventors: Stephen E. McGuire; John C. primary Examiner R0bert m stauter; Carl Kennedy of Attorney, Agent, or Firm-Ronald J. Carlson Ponca City, Okla. [73] Assignee: Continental Oil Company, Ponca City, Okla- 57 ABSTRACT 22 Filed: Sept. 11, 1972 0 M b x1 e copper ores 1n su m e orm may e concen- [211 APPL 288,200 trated in a flotation separation process by sIurrying said ores in an aqueous solution of a flotation reagent [52] U.S. CI. 209/166 o ed y generating gas bubbles in the slurry to [51] Int. Cl B03d l/02 l at th xide opper and recovering the concen- [58] Field of Search 209/ 166, 167 trated i e ppe ro the surface of the y.

wherein the floatation reagent is [56] References Cited MW" n 2 .2 m.*

UNITED STATES PATENTS (I) 1,952,907 3/1934 Christmann 209/166 1,960,526 5/1934 Christmann 209/166 2,267,205 12/1941 Kyrides 209 166 x MAW,

2,337,118 12/1943 Lontz 209/166 II. condensation reaction products of 2,414,199 H1947 Gutzeit; 209/166 amines of the structure 2,569,417 9/1951 Jayne 209/166 H2N(CH2CH2NH)HH, and

3,425,549 2/1969 DlCkSOII 209/166 g i halides of the structure FOREIGN PATENTS OR APPLICATIONS 481,623 3/1952 Canada 2b9/I66 9 Claims, N0 Drawings CONCENTRATION OF OXIDE COPPER ORES BY FLOTATION SEPARATION This invention relates to the novel use of certain compounds as flotation reagents in producing oxide copper ore concentrates by flotation separation and, in particular, to producing copper concentrates by flotation separation of ores containing copper in oxidized form such as malachite, azurite, cuprite, tenorite and chrysocolla.

Heretofore, flotation separation techniques for concentrating copper ores have been applied to sulfide copper ores due to the availability of suitable flotation reagents, or collectors as they are sometimes called, for these ores such as the xanthates. Generally, in the typical flotation technique the raw ore containing gangue rock along with the copper ore is first pulverized to a finely divided form and slurried with water to form a pulp. The pulp is then charged to a flotation cell along with the flotation reagent and usually a frother (e.g., a hydroxy compound) and a regulating agent to control the pH. With agitation of the slurry the particles of sulfide copper ore are floated to the surface through the action of the flotation reagent, become suspended in the froth and are then continuously removed from the surface of the slurry. The undesired gangue remains behind in the slurry and is discarded in the tailings from the cell.

While the above-described flotation techniques have been in general use in concentrating sulfide copper ores, they have not been utilized to any extent with oxide copper ores. This has been primarily due to the lack of suitable flotation reagents for the direct flotation of the oxide copper ores since these ores are not as readily floated as the sulfide ores. It has been reported in the literature that mercaptobenzothiazole and salts of fatty acids have sometimes been found effective for direct flotation of the oxide ores but, in general, the oxide ores are first subjected to sulfidization to convert them to the sulfide ores and then concentrated by the usual flotation techniques and reagents. This approach obviously has drawbacks and there is considerable interest in the mining industry in developing direct flotation techniques for oxide copper ores.

In accordance with this invention, it has unexpectedly been found that certain compounds are highly effective as flotation reagents concentrating oxide copper ores by flotation separation without the necessity of first subjecting such oxide ores to a sulfidization treatment. These compounds may be described as wherein R is hydrogen or a CH COOX radical; X is hydrogen or an alkali metal atom such as sodium, potassium or lithium; and R is an alkyl radical having six to 18 carbon atoms or a 2 radical wherein R is hydrogen or an alkyl radical having one to 14 carbon atoms and R is an'alkylene radical having one to 15 carbon atoms, with the total number of carbon atoms of both R and R being in the range of three to 15; and

II. the condensation reaction products of polybasic amines and organic halides.

The compounds of group (I) and their preparation are known in the art as shown in US. Pat. Nos. 2,804,474 and 3,228,904. In general, they may be prepared by reaction of a primary amine with a halosubstituted carboxyl-containing compound. Exemplary of the primary amine reactants RNH are octyl amine, dodecyl amine, octadecyl amine, hexyl amine, ethylbenzyl amine, 2-ethylhexyl amine, tetramethyloctyl amine and butylbenzyl amine. The halogen substituted carboxyl-containing compounds include chloroacetic acid, iodoacetic acid, bromoacetic acid, sodium bromoacetate, potassium chloroacetate and sodium chloroacetate.

The condensation reaction products of group (II) are derived from polybasic amines of the structure H N(CH CH NH),,H wherein n is an integer of Ho 6 and organic halides of the structure R Y wherein R is as described above in connection with the group (I) compounds and Y is a halogen atom such as bromine or chlorine. The preparation of these compounds involves standard condensation reaction techniques and is described in the examples hereinafter. Exemplary of the polybasic amine reactants are ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine and hexaethylene heptamine. Among the suitable organic halides defined above are included dodecylbenzyl chloride, octyl bromide, tetradecyl bromide, octadecyl chloride, 2- ethylhexyl chloride, hexylbenzyl chloride, hexyl bromide, dodecyl chloride, decylbenzyl chloride, tridecylbenzyl chloride and 2-butyloctyl bromide.

The above-described compounds have been found useful in flotation separation techniques to concentrate oxide copper ores and, particularly, for concentrating low grade ores containing considerable gangue. These low grade ores may contain as little as 1% percent copper or less, expressed as CuO. As previously indicated,

flotation separation generally involves subdividing the raw ore, most desirably to an extent wherein each particle is composed as nearly as possible of either the valuable orworthless material only. The subdivided ore is slurried in water, or the water may be added during the subdividing, so as to form a pulp which will normally contain about 10 to percent solids by weight. The flotation reagent is then added to the pulp and gas bubbles are either generated or introduced in the pulp whereby the solid particles containing the oxide copper ore adhere to the gas bubbles and rise to the surface of the pulp for easy removal as a concentrated oxide copper ore. These techniques are well-known in the art and a more complete and detailed discussion may be found in Flotation by A. M. Gaudin, Second Edition, [957, published by McGraw-l-lill. It is also desirable to employ a frothing agent and a pH regulating agent in these techniques as explained in that text. A partial list of some common frothers and regulating agents is presented at page 154 of An Introduction to the Theory of Flotation by Klassen and Mokrousov, Second Edition, 1963, published by Butterworth and Co. Ltd. (Lon don).

In general, the compounds may be used as the flotation reagent in the flotation separation process in any amount which is suitable to provide the desired flotation of the oxide copper ore. Of course, for economic reasons the amount employed should be the minimum required to achieve the desired results. Generally, amounts in the range of about 0.01 to about pounds per ton of ore will usually be employed with a range of about 0.05 to about 2 pounds per ton of ore being normally preferred. The amount of flotation reagent and the degree of flotation achieved will be dependent, in part, on the pH of the flotation slurry. Thus, in optimizing a particular separation process it is recommended that a series of simple experiments be run using a conventional Hallimond cell, first determining the optimum pH range with a constant flotation reagent concentration and then determining the optimum flotation reagent concentration at a constant optimum pH. These experiments can be conducted as described in the examples to follow.

The following examples will further illustrate the invention:

EXAMPLE 1 Preparation of Flotation Reagent A condensation reaction product of group 11 was prepared in a 100 ml flask equipped with a magnetic stirrer, condenser with drying tube, thermometer and dropping funnel by charging to the flask 0.055 mol KOH and 50 ml absolute ethanol. The flask was heated to 70C and stirred to dissolve the KOH. 0.05 mol of ethylene diamine was added as one portion and 0.05 mol of dodecylbenzyl chloride was then added dropwise. After addition of the dodecylbenzyl chloride, the reaction mixture was stirred for about 2 hours at 70C, then cooled to about 25C and stirred for another hour. The KCl formed in the reaction was removed by filtration and the resulting clear liquid was stripped of solvent to recover the condensation reaction product.

The dodecylbenzyl chloride used in the preparation was a commercially produced material prepared by chloromethylation of a commercially available alkylbenzene derived from propylene tetramer wherein the alkyl has an average of 12 carbons (Conoco AB 515).

the deslimed mineral to a beaker along with ml aqueous solution of the condensation reaction product having a concentration of l X 10 mol/liter. The pH of the flotation slurry was then adjusted to the desired value using HCl for pH values of 3-4, NaCO for pH values of 5-9 and KOH for pH values of 10-13. The slurry was stirred for a few minutes for preconditioning and then charged to the modified Hallimond cell. Then a total of about 100 cc of air was bubbled through the slurry over a period of 3 minutes during which time the particles of Chrysocolla were floated and recovered through the upper side arm of the cell. Kt the end of the 3-minute period the test was terminated and t he recovered Chrysocolla which was floated was dried and weighed. The remaining Chrysocolla which was not floated was also recovered, dried and weighed. Based on these two determinations the percent recovery (floated Chrysocolla) was calculated. The results of the tests are set forth in the following table:

TABLE I pH Recovery pH Recovery EXAMPLE 2 TABLE II Recovery Recovery Recovery Recovery pH (l l0 Conc) (3X10 Cone) pH 1X10 Cone) (3X10 Conc) Flotation Separation Tests EXAMPLE 3 The seat/5565556"eoriaensanan reaction product was evaluated as a flotation reagent in a series of tests involving various pH values using a conventional modified Hallimond tube flotation cell. In each test a flotation slurry was first prepared and then transferred to the cell. The flotation slurry was prepared by desliming a l g sample of -48 (Tyler) mesh Chrysocolla (CuSiO 2H O) with distilled water and then charging Preparation of Flotation Reagent A condensation reaction product of group 11 was prepared as described in Example 1 except that 0.05 mol triethylene tetramine was substituted for ethylene diamine. Flotation Separation Tests:

A dual series of flotation separation tests were run as described in Example 2 using the above prepared condensation reaction product reagent. The results are tabulated in Table 111.

TABLE 111 Recovery Recovery Recovery Recovery EXAMPLE 4 treated with aqueous sodium hydroxide tocon veitthe Preparation of Flotation Reagent A condensation reaction product of group II was prepared as described in Example 1 except that 0.05 mol tetraethylene pentamine was substituted for ethylene diamine. Flotation Separation Tests A dual series of flotation separation tests were conducted as described in Example 2 using the above condensation reaction product reagent. The results appear in Table IV.

ester to the sodium salt of ,N-tetradecyliminodiacetic acid. Some small amounts of tetradecyliminomonoacetic acid were also present. Flotation Separation Tests TABLE Recovery Recovery Recovery Recovery ph (1X 1 0"Conc) (3X l 0 Conc) pH (lXl0 Conc) (3 lO' Conc) A EXAiiifiLE '5' TABLE VI Preparation of Flotation Reagent R A condensation reaction product of group [1 was pre- Reagem eagflm 1 7 c 1 '7 R pared as described 1n Example 1 usmg 0.05 mol dode- Conc(m/ C Recovery 0mm) ovary cylbenzyl chloride, 0.05 mol triethylene tetramine and 40 1 10j 3.1 2x10: 44. 2 0.055 mol KOH. The dodecylbenzyl chloride was degag; if; @113 32;; rived by alkylating benzene with dodecene-l in the 7 ur 5.9 7x10 100.0 presence of AlCl and then chloromethylating the 1X10" product.

Flotation Separation Tests:

A series of flotation tests using the above prepared EXAMPLE 7 reagent were conducted as described in Example 1. The results are shown in Table V.

TABLE V pH Recovery 7 pH Recovery EXAMPLEE m i Preparation of Flotation Reagent A composition of group I was prepared as described in Example 6 except that hexadecyl amine was substituted for tetradecyl amine. The reagent product was the sodium salt of N-hexyldecyl iminodiacetic acid. Flotation Separation Tests A series of flotation tests were performed as described in Example 1 using the above condensation reaction product as reagent. However, in this series of tests Malachite (CuCO Cu(OH) was used as the oxide copper ore, the pH was a constant 9 and the concentration of the reagent was varied. The results appear in Table VIl.

TABLE V11 Reagent Reagent Conc(m/l) Recovery Conc(m/l) Recovery 1 10- 6.9 3 10- 26.6 3X10 5.3 lXlO" 63.4 1X10" 4.8 2 10 73.5 3Xl0 3.5 2.5Xl0 94.3 lXlO l3.6

sodium N- 7 V 7 EXAMPLE 8 Preparation of Flotation Reagent A composition of group I was prepared as described in Example 6 except that hexyl amine was substituted for tetradecyl amine. The reagent product was the so- TABLE VIII Preparation of Flotation Reagent A composition of group I was prepared as described in Example 6 except that octyl amine was substituted for tetradecyl amine. The reagent product was the sodium salt of N-octyl iminodiacetic acid. Flotation Separation Tests A series of flotation separation tests were performed according to the procedure of Example 1 using the above described condensation reaction product as reagent. However, in this series of tests Malachite (CuCO Cu(Ol-l) was used as the oxide copper ore, the pH was a constant 9 and the concentration of reagent was varied. The results appear in Table IX;

TABLE IX Reagent Reagent Conc( m/l) %Recovery Conc( m/l) %Recovery 3X10 21.5 3X10 3.7 1X10" 33.3 1X10 4.5 3X10 44.6 5X10" 47.4 1X10 74.6 7X10" 55.9 3Xl0 100.0 2X10 100.0

EXAMPLE 10 product as reagent. The results appear in Table X.

TABLE x Reagent Reagent Conc(m/l) Recovery Conc(m/l) Recovery EXAMPLE 11 Preparation of Flotation Reagent A composition of group I was prepared as described in Example 6 except that dodecyl amine was substituted for tetradecyl amine. The reagent product was the sodium salt of N-dodecyliminodiacetic acid. Flotation Separation Tests Several flotation separation tests were run as described in Example 1 using the above condensation reaction product as reagent except that the reagent concentration employed was 2 X 10' mol/liter. In addition to a series of tests with Chrysocolla, a series was performed on each of Malachite, Azurite (2CuCO Cu (OI-D Cuprite (Cu O) and Tenorite (CuO). The results appear in the following table.

Table XI Oxide Copper Ore Chrysocolla 1CuSiO -ZH OI pH Recovery pH Recovery Oxide Copper Ore Malachite (CuCOrCulOHh) DH Recovery pH Recovery 4.7 21.7 9.2 100.0 5.9 22.0 10.1 90.5 7.2 100.0 11.1 38.5 8.1 100.0 12.1 65.1 Oxide Copper Ore Azurite 2CuCOCu OH 1,! DH Recovery DH Recovery 4.0 12.8 9.0 89.8 5.2 19.4 10.2 88.4 6.1 72.7 11.1 61.8 7.4 85.0 12.2 38.7

Oxide Copper Ore Cuprite QCUIOI DH Recovery DH Recovery 3.2 17.4 8.0 100.0 4.1 6.1 9.0 77.4 5.0 91.7 10.0 66.6 5.3 100.0 11.0 45.3 5.9 100.0 12.1 17.7 6.8 100.0

Oxide Conner Ore Tenorite (CuO) DH Recovery DH Recoveg 3.0 79.1 9.0 73.2 4.0 76.6 9.4 87.4 5.0 69.3 10.0 70.9 6.1 35.6 11.0 44.4 7.2 37.9 12.1 64.9

EXAMPLE 12 Condensation reaction products formed by reacting dodecyl chloride with triethylene tetramine or tetradecyl bromide with diethylene triamine may typically be used as flotation reagents in the flotation separation of chrysocolla or malachite.

EXAMPLE 13 '7 N-decyliminodiacetic acid, N-octyliminodiacetic acid, N-dodecylbenzyliminodiacetic acid and potassium N-octybenzyl-iminodiacetate may typically be used as flotation reagents in the flotation separation of malachite, chrysocolla or azurite.

Thus having described the invention in detail, it will be understood by those skilled in the art that certain variations and modifications may be made without departing from the spirit and scope of the invention as described herein and in the appended claims.

We claim:

1. In a flotation separation process wherein oxide copper ores in subdivided form are concentrated by slurrying said ores in an aqueous solution of a flotation reagent followed by generating gas bubbles in the slurry to float the oxide copper and recovering the concentrated oxide copper from the surface of the slurry, the improvement therein which comprises employing a flotation reagent defined by condensation reaction products of A. polybasic amines selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, pentaethylene hexamine and hexaethylene heptamine; and

B. organic halides of the structure where R is hydrogen or an alkyl radical having one to 14 carbon atoms and R is an aliphatic hydrocarbon radical having one to 15 carbon atoms, with the total number of carbon atoms of both R and R being in the range of three to 15; and Y is a halogen atom.

2. A process accordingto claim 1 wherein the polybasic amines are selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine.

3. A process according to claim 1 wherein R is an alkyl radical having six to 18 carbon atoms and Y is radical and Y is bromine or chlorine.

5. A process according to claim 4 wherein R has one carbon atom.

6. A process according to claim 5 wherein R is an alkyl radical having eight to 14 carbon atoms.

7. A process according to claim 1 wherein about 0.01 to about 5 pounds of flotation reagent per ton of raw ore are employed.

8. In a flotation separation process wherein oxide copper ores in subdivided form are concentrated by slurrying said ores in an aqueous solution of a flotation reagent-followed by generating gas bubbles in the slurry to float the oxide copper and recovering the concentrated oxide copper from the surface of the slurry, the improvement therein which comprises employing a flotation reagent defined by omcoox 9. A process according to claim 8 wherein R has one carbon atom. 

2. A process according to claim 1 wherein the polybasic amines are selected from the group consisting of ethylene diamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine.
 3. A process according to claim 1 wherein R2 is an alkyl radical having six to 18 carbon atoms and Y is bromine or chlorine.
 4. A process according to claim 1 wherein R2 is a
 5. A process according to claim 4 wherein R4 has one carbon atom.
 6. A process according to claim 5 wherein R3 is an alkyl radical having eight to 14 carbon atoms.
 7. A process according to claim 1 wherein about 0.01 to about 5 pounds of flotation reagent per ton of raw ore are employed.
 8. In a flotation separation process wherein oxide copper ores in subdivided form are concentrated by slurrying said ores in an aqueous solution of a flotation reagent followed by generating gas bubbles in the slurry to float the oxide copper and recovering the concentrated oxide copper from the surface of the slurry, the improvement therein which comprises employing a flotation reagent defined by
 9. A process accoRding to claim 8 wherein R4 has one carbon atom. 